Perhaps you should try some spelling variations:
khanh phuong » khanh phong, khanh phung, khanh thuong
thanh phuong » thanh huong, thanh chuong, khanh phong
khoi doanh » hoa doanh, cho doanh, voi doanh
doanh gian » doanh giao, doanh giai, dan gian
cach hoc » cach thuc, cach thoi, dich hoc
cuu toan » cuu hoan, cua toan, huu toan
toan hoc » toan khoa, van hoc, hoa hoc
mai khoi » mai khoa, tai khoa, cac khoi
gian dan » gian lang
tu cach » tu cac
hoa mai » hoa dai, hoa may, hoa moi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu cach hoc tap, nghien cuu toan hoc ((khanh phuong) OR (thanh phuong)) hoa mai khoi doanh gian dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cach hoc tap, nghien cuu toan hoc ((khanh phuong) OR (thanh phuong)) hoa mai khoi doanh gian dan".
• Adding a wildcard symbol may retrieve word variants: tu cach hoc tap, nghien cuu toan hoc ((khanh phuong) OR (thanh phuong)) hoa mai khoi doanh gian dan*.